[Bug other/12096] New: dejagnu truncates output from spawned commands randomly, causing intermittant failed tests

[dank at kegel dot com]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12096

           Summary: dejagnu truncates output from spawned commands randomly,
                    causing intermittant failed tests
           Product: gcc
           Version: 3.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: other
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dank at kegel dot com
                CC: gcc-bugs at gcc dot gnu dot org

This is most likely a bug in expect, not in any part of gcc,
but it deserves mention here nonetheless. 
Tests which tend to be affected by this are those that generate
lots of output.  I've observed it cause the following most often:

FAIL: gcc.dg/cpp/tr-warn3.c 
FAIL: gcc.dg/format/c90-printf-1.c 
FAIL: gcc.dg/format/c99-printf-1.c
FAIL: gcc.dg/format/ext-1.c
FAIL: gcc.dg/format/ext-3.c 
FAIL: gcc.dg/format/ext-6.c 
FAIL: gcc.dg/noncompile/voidparam-1.c
FAIL: gcc.dg/typespec-1.c
FAIL: g++.law/visibility19.C

and the failures usually are marked with 'test for warnings'
or 'test for excess errors', e.g.

FAIL: gcc.dg/format/ext-3.c bad %^# (test for warnings, line 215)
FAIL: gcc.dg/format/ext-3.c (test for excess errors) 

See also
http://gcc.gnu.org/ml/gcc/2001-02/msg01313.html
http://gcc.gnu.org/ml/gcc/2002-09/msg00653.html
http://mail.gnu.org/archive/html/dejagnu/2003-07/msg00020.html

One workaround might be to install the latest expect, but 
I haven't tried that.
FWIW, on one system I'm seeing this on, 'expect -version' outputs
"expect version 5.32.2"
which is probably as old as the oldest report I cite above,
so updating expect might indeed help.